anaytical methods for metal detection

• flame atomic absporption spectrophometry

• electrothermal atomic absorption spectrophometry

• inductively coupled plasma atomic emission spectrometry

• atomic fluorescence spectrometry

detection methods

Mycotoxins

- TPC
- HPLC
- ELISA

Paralytic shellfish toxins (PSPs)

- HPLC (oxidation and fluorscence assay)
- Capillary electrophoresis

Diarrhetic shellfish

- LC
- Mass spectrometry (can use to detect all but expensive)

Herbicide residue/fungicide reside

- LC
- GC

meaning

An enterotoxin is a protein toxin released by a micro-organism in the lower Intestine. Enterotoxins are frequently cytotoxic and kill cells by altering the permeability of the epithelial cells of the intestinal wall. They are mostly pore forming toxins, secreted by bacteria, that assemble to form pores in cell membranes. This causes the cells to die.


A neurotoxin is a toxin that acts specifically on nerve cells – neurons– usually by interacting with membrane proteins such as ion channels.


meaning from: http://en.wikipedia.org/wiki/Enterotoxins
http://en.wikipedia.org/wiki/Neurotoxins

bacterial toxins

Staphylococcus aureus intoxication

- One of the most important causes of food-borne disease worldwide.
- It is gram positive, nonmotile and non-spore forming cocci that forms 5entertoxins ( A-SEA, SEB, SEC, SED, SEE)
- Entertoxins are simple proteins that have high heat stability
- Growth increases at optimum pH and temperature
- Foods containing S.aureus at level of 5 X 105/g may cause S.aureus intoxication

Signs and symptoms

- begin 1-6hrs of consumption
- nausea, vomiting, abdominal cramps, diarrhea

Preventive measures

- practice hygiene practices
- reduced post-cooking contamination of high protein foods and eliminating prolonged storage of cooked food at room temp before eating

Clostridium botulinum intoxication

- gram positive rod-shaped anaerobic bacteria capable of forming heat resistance spores
- 6types of heat labile neurotoxins : A, B, C, D, E, F and G
- Type A and B : more likely to cause botulism in humans
- Example of food containing type A and B: beans and corns
- Type E : isolated from soil, seawater, fish intestines and sea or lake sediments
- Type F : from liver paste
- Botulinum toxin is a super toxin compound.
- Prevention : heating at 79oC for 20mins or at 85oC for 5mins

Signs and symptoms

- Appears 12-24hrs following consumption
- headache, blur vision, dizziness
- causes death from periods 24hrs to 2-3weeks

Preventive measures

- proper home preservation of foods
- discard all swollen and damaged canned products

Bacillus cereus intoxification

- gram positive, rod shaped, spore forming aerobe
- found in cereals, milk, herbs and spices
- 2types of enterotoxins : emetic and diarrheagenic
- Diarrheagenic toxins is a protein that is produced by actively growing cells
- Activated by enzymes like trypsin or exposure to 56oC or more than 30mins
- Emetic toxin is stable to heat, pH and pepsin enzymes

Clostridium perfringens intoxication

- causes foodborne infections followed that subsequently lead to sporulation
- lecithinase, an enterotoxin released during sporulation
- five antigenically (toxicologically) types: type A through E
- type A: involve in foodborne gastroenteritis in humans
- type C: produces 2 different toxins; lethal-necrotizing and hemolytic



book: introduction to toxicology and food

mycotoxins found in food and animal feed

Aflatoxins

-Possible adverse effects on livestock health and productivity
-Toxins produced by species of Aspergillus, mainly A.flavus and A. parasiticus
-There are 17toxins present but only 4 considered widespread and toxins ( ie aflatoxins B1, B2, G1. G2)
-Pure aflatoxins are destroyed by UV radiations, unstable at pH<3>10 and in the presence of oxidizing components.
-The toxins have native fluorescence, which is used for their analysis and for the sorting of contaminated units.
-Aflatoxins occur in wide variety of commodities including cereals, nuts and oilseeds

Ochratoxin A (OTA)

- Variety of moulds included in the genera Aspergillus
- Ochratoxin A contaminated crops include cereal such as barley and maize, wheat and oat.
- In cereals, OTA is produced more frequently by Penicillium than Aspergillus (generally occurs as storage contamination)

Trichothecenes

- Wide group of mycotoxins produced by various species of different genera: Fusarium, Myrothecium, Stachybotrys, Trichoderma, Cephalosporium, Trichothecium and Verticimonosporium ( Betina, 1993)

Fumonisins (FBs)

- FBs are mycotoxins mainly produced by Fusarium verticillioides, Nirenberg, Fusarium proliferatum
- Occurs in mainly maize and maize based food products at levels that could affect human and animal health.



book: pesticide, veterinary and other residues in food

What’s the Bottom Line on GM Crops and GM Foods?

1. SAFETY: To the best of our knowledge, GM foods and crops are as safe as conventional ones. Nutritionists and other scientists do not know of any unresolved safety issues.

2. REGULATION: GM crops and foods are highly regulated by the United States and other governments. The approval process requires many tests and takes many years. Scientists and agricultural biotech
companies support such regulations.

3. ENVIRONMENT: There is no evidence that GM crops harm the environment or have the potential to harm the environment any more than traditional agriculture.

4. ENVIRONMENTAL BENEFITS: Certain GM crops have environmental benefits because they require less pesticide to be used and less tilling of the land (and therefore less danger of erosion). GM crops can play an important role in making agriculture more sustainable and more productive.

5. BETTER NUTRITION: In the near future, GM crops and foods derived from them will have higher levels of vitamins, minerals, biologically active phytochemicals, and other nutrients.Many allergens will be eliminated.

6. FARMERS:Most farmers want GM crops because they make crop production cheaper. For their own safety, they especially like crops that require less pesticide.

7. OPPONENTS OF GM CROPS: Groups that oppose GM crops on ideological, philosophical, or economic grounds (such as Greenpeace and the Sierra Club) have not brought forth scientific evidence to back up their claims of negative health consequences or environmental impact.

8. DEVELOPING COUNTRIES: Plant breeders and farmers want access to GM technology to improve their crops. Everyone knows that this will not solve world hunger. It is simply another tool to increase productivity and reach that goal.


extracted from: http://www.sdcma.org/GMFoodsBrochure.pdf

The National Seed List

Committee	Department	Responsibility
Advisory Committee on Genetic modification	Health and Safety Executive	Advises on all aspects of human and environmental safety of contained use (eg in the laboratory) of GMOs
Advisory Committee on Releases into the environent	DEFRA	Advises on the environmental safety of proposed releases, marketing of GMOs, and related issues
Advisory Committee on Novel Foods and Processes	Food Standards Agency	Advises on the safety of novel foods such as those derived from GMOs
Advisory Committee on Animal Feedingstuffs	Food Standards Agency	Advises on the safety and use of animal feeds
Advisory Committee on Pesticides	DEFRA	Advises the Government on the use of pesticides and herbicides
Agriculture and Environment Biotechnology Commission	Department of Trade and Industry	Advises the Government on strategic developments in agricultural biotechnology and environmental implications

The information is finally in table- form!! =))

PS: DEFRA stands for Department for Environment Food and Rural Affairs